PITTSBURGH (KDKA) — A retired judge admitted to buying an AR-15 for his boyfriend, a convicted felon who authorities say had a Nazi obsession.

Karl Alexander pleaded guilty in federal court on Friday.

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Alexander wrote on an official form that he was buying the gun for himself.

But he really bought it for Dennis Riggs, a convicted felon.

His home was raided last month by officials.

According to the criminal complaint, on Jan. 22, FBI Special Agents and Task Force Officers executed a federal search warrant at Riggs’ home in Troy Hill.

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During the search, law enforcement located seven firearms: a Ruger .223 Caliber AR-15 style rifle; a Ruger .22 caliber revolver; a Harrington & Richardson shotgun; a .38 special revolver; a Colt .38 Caliber revolver; a US revolver, 32 Caliber, which was loaded with the hammer cocked; and a Harrington & Richardson shotgun.

Agents also located multiple rounds of ammunition in the residence. Riggs is prohibited from possessing a firearm because he was convicted on March 30, 1994, of aggravated assault.

Agents found on his phone a video depicting Riggs wearing Nazi apparel, offering Nazi salutes and loading and unloading an AR-15 style rifle.

They also found a video of the 2019 Christchurch and New Zealand mosque shootings which killed 51, images of the defendant with firearms and a photograph of Dylann Roof with his current Bureau of Prisons contact information.

Roof was convicted in the 2015 massacre at Emanuel African Methodist Episcopal Church in Charleston, South Carolina.

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Riggs decorated his house with Nazi and Hitler posters and pictures, possessed numerous other weapons, knives and daggers, and had hundreds of bottles of liquor and alcohol.